Abstract The lack of defending in bystanders to cyberbullying has been linked with the process of moral disengagement, which allows bystanders to justify the morality of their inactivity after witnessing a cyberbullying episode. Context is central in this process as individuals assess the specific contextual cues present within each episode, and it is this assessment that informs their subsequent behavior. Despite the importance of context in moral disengagement, researchers have yet to take this factor into account. To address this gap in literature, the present study examines the role of contextual factors on moral disengagement in specific cyberbullying episodes, and how this process influences cyber defending. This study also consolidates inconsistent results from studies examining moral disengagement and defending by examining defending as a multifaceted construct involving aggressive and constructive defending. To examine these issues, 540 Grade 7 and 9 students completed a survey assessing moral disengagement and defending self-efficacy in two cyberbullying scenarios. Results revealed that in both scenarios, contextualized moral disengagement is shown to be associated with aggressive and constructive defending self-efficacy above and beyond general moral disengagement. Higher levels of contextual moral disengagement are also related to greater aggressive defending self-efficacy whereas lower contextual moral disengagement is linked with greater pro-social defending self-efficacy. These results call for an increased focus on contextual factors when examining morality in cyberbullying and highlight the need to differentiate between pro-social and aggressive forms of defending.